Caudron C.860
| Caudron C.860 | |
|---|---|
| Role | Long range communication aircraft |
| National origin | France |
| Manufacturer | Société des Avions Caudron |
| Designer | Marcel Riffard |
| First flight | 6-10 September 1938 |
| Primary user | Air Ministry |
| Number built | 1 |
| Developed from | Caudron Simoun and Rafale |
The Caudron C.860 was a single engine, single seat monoplane ordered by the French government as a long distance communications aircraft. First flown in 1938, it was also expected to set speed and altitude records but the outbreak of World War II ended developments.
Design
[edit]The C.860 was ordered by the French Air Ministry who planned to use it, piloted by André Japy, for rapid long distance communications. Powered by a 9.5 L (580 cu in) Renault 6Q-03 engine, it had a range of up to 8,000 km (5,000 mi; 4,300 nmi) when cruising at 290 km/h (180 mph; 160 kn). It was also expected to set distance and altitude records in Category 1 with a 8.0 L (490 cu in) Renault engine and in Category 2 with a 6.5 L (400 cu in) Renault,[1] but war intervened.
Its wing and empennage were aerodynamically similar to those of the Caudron Simoun, though the single-piece wing was structurally closer to that of the record-setting Rafale racer. The wing was tetragonal in plan, with more sweep on the trailing edge than on the leading edge, though the tips were semi-elliptical. It had an all-wood structure with a single box spar which incorporated an upper flange of gumbo-limbo, a Central and South American wood of particularly high bulk modulus, together with spruce and plywood ribs. The ply skin was finished with a fabric overlay. Its ailerons were carried on auxiliary spars.[1]
The C.860's fuselage was slender, with a maximum width of only 850 mm (33 in) and about one third of it ahead of the wing leading edge. Its 180 kW (240 hp) 9.5 L (580 cu in) air-cooled six-cylinder Renault 6Q-03 inverted in-line engine, supercharged to 2,000 m (6,600 ft), was in the nose with its main and collector fuel tanks behind it over the centre of gravity. Together with four smaller wing tanks, these gave a fuel capacity of 1,500 L (330 imp gal; 400 US gal). The pilot had an enclosed cockpit with his head raised only slightly above the fuselage under a shallow canopy with a horizontal strip of plexiglas for forwards and sideways vision, a solid top and an extended fairing aft. There were also windows in the fuselage sides for downward views.[1]
The fuselage had a wooden frame with canvas covered sides and curved magnesium sheet top and bottom. The empennage of the C.860 was conventional, with a straight-tapered, blunt-tipped horizontal tail carrying separate elevators. The tall vertical tail had a similar shape though, unlike the elevators, the rudder was balanced. The aircraft had a fixed, tailwheel undercarriage with a 2 m (6 ft 7 in) track. Messier oleo strut landing legs were mounted on the wing spar. Legs, mainwheels and the steerable tailwheel, also on an oleo strut, were enclosed in fairings.[1]
Development
[edit]By 5 September 1938 the C.860 had been brought, still not quite complete, from the Caudron factory at Issy-les-Moulineaux to the airfield at Guyancourt.[2] The first flight had been made, piloted by Delmotte, by 10 September.[3] Its initial tests had been completed by the end of September, when the C.860 entered the Centre d'Essais de Matériels Aériens (CEMA), the French official testing centre at Villacoublay.[4] These tests temporarily finished at the beginning of January 1939[5] but the C.860 returned to CEMA at the end of the month.[6]
With certification complete, the Air Ministry took the C.860 to Istres to determine the take-off run required with the heavy fuel load needed to achieve the desired long range.[7] A 24.5 hour flight at 290 km/h (180 mph), covering 7,100 km (4,400 mi), consumed 1,340 L (290 imp gal; 350 US gal) of petrol and 80 L (18 imp gal; 21 US gal) of oil. The resulting take-off weight of 2,300 kg (5,100 lb), required a take-off run of 650 m (2,130 ft), well within the Air Ministry's 1,000 m (3,300 ft) specification limit.[1]
Specifications
[edit]Data from Les Ailes 8 June 1939[1]
General characteristics
- Crew: One
- Length: 8.60 m (28 ft 3 in)
- Wingspan: 10.40 m (34 ft 1 in)
- Height: 3.28 m (10 ft 9 in)
- Wing area: 16 m2 (170 sq ft)
- Empty weight: 1,160 kg (2,557 lb)
- Gross weight: 1,650 kg (3,638 lb) for certification tests, up to 2,400 kg (5,300 lb) for distance records
- Fuel capacity: 1,500 L (330 imp gal; 400 US gal)
- Powerplant: 1 × Renault 6Q-03[8] 9.5 L (580 cu in) air-cooled six-cylinder, inverted in-line piston engine, supercharged to 2,000 m (6,600 ft), 180 kW (240 hp)
- Propellers: 2-bladed Ratier, metal, electrically driven variable pitch
Performance
- Maximum speed: 340 km/h (210 mph, 180 kn) at 2,500 m (8,200 ft)
- Cruise speed: 290 km/h (180 mph, 160 kn)
- Range: 7,100 km (4,400 mi, 3,800 nmi) at a weight of 2,300 kg (5,100 lb)
- Take-off distance: 340 m (1,120 ft) at 1,650 kg (3,640 lb); 650 m (2,130 ft) at 2,300 kg (5,100 lb)
References
[edit]- ^ a b c d e f Frachet, André (8 June 1939). "L'avion de performance Caudron "C-860"". Les Ailes (938): 9.
- ^ Phillipe Roland (5 September 1938). "AVIATION". Le Figaro.
- ^ Phillipe Roland (11 September 1938). "AVIATION". Le Figaro.
- ^ "Les avions en essais". Les Ailes (902): 10. 29 September 1938.
- ^ "Les avions en essais". Les Ailes (919): 8. 5 January 1939.
- ^ "Les avions en essais". Les Ailes (922): 9. 6 February 1939.
- ^ "Les avions en essais". Les Ailes (929): 9. 6 April 1939.
- ^ Bruno Parmentier. "Caudron C.860". Retrieved 30 May 2016.